import java.util.Scanner;

/**
 * \* Created with IntelliJ IDEA.
 * \* User: Administrator
 * \* Date: 2022/1/7
 * \* Time: 13:09
 * \* To change this template use File | Settings | File Templates.
 * \* Description:
 * \
 */
public class TestDemo {
    public static void main(String[] args) {
        //测试
        //先创建一个ArrayStack对象-》表示栈
        ArrayStack stack= new ArrayStack(4);
        String key="";
        boolean loop=true;//控制是否退出菜单
        Scanner scanner = new Scanner(System.in);

        while(loop){
            System.out.println("show: 表示显示栈");
            System.out.println("exit: 退出程序");
            System.out.println("push: 表示添加数据到栈（入栈）");
            System.out.println("pop: 表示从栈中取出数据");
            System.out.println("请输入你的选择");
            key=scanner.next();
            switch (key){
                case "show":
                    stack.list();
                    break;
                case "push":
                    System.out.println("请输入一个数：");
                    int value=scanner.nextInt();
                    stack.push(value);
                    break;
                case"top":
                    try {
                        int res=stack.pop();
                        System.out.println("出栈的数据时"+res);
                    }catch (Exception e){
                        System.out.println(e.getMessage());
                    }
                    break;
                case "exit":
                    scanner.close();
                    loop = false;
                    break;
                default:
                    break;
            }
        }
        System.out.println("程序退出");
    }
}

//定义一个ArrayStack 表示栈
class ArrayStack{
    private int maxSize;// 栈的大小
    private int[] stack;//数组，数组模拟栈，数据就放在该数组
    private int top=-1;//top表示栈顶，初始化为-1

    //构造器
    public ArrayStack(int maxSize){
        this.maxSize=maxSize;
        stack = new int[this.maxSize];
    }

    //栈满
    public boolean isFull(){
        return top==maxSize-1;
    }
    //栈空
    public boolean isEmpty(){
        return top==-1;
    }
    //入栈
    public  void push(int value){
        //先判断栈是否满
        if(isFull()){
            System.out.println("栈满");
            return;
        }
        top++;
        stack[top]=value;
    }
    //出栈,将栈顶的数据返回
    public int pop(){
        //先判断栈是否空
        if(isEmpty()){
            //抛出异常
            throw new RuntimeException("栈空，没有数据");
        }
        int value =stack[top];
        top--;
        return value;
    }
    //显示栈的情况——遍历栈,遍历时，需要从栈顶开始显示数据
    public void list(){
        if(isEmpty()){
            System.out.println("栈空，没有数据");
            return;
        }
        for(int i=top;i>=0;i--){
            System.out.printf("stack[%d]=%d\n",i,stack[i]);
        }
    }
}

